In recent years, organic field effect transistors (OFETs) composed of conjugated polymers, oligomers, or small organic molecules have some unique advantages and thus much attention has been paid thereto by researchers. They can be processed at room temperature, bendable, and low-cost, and can be subjected to mass production. They can be used in drive circuits of flat panel displays, as memory elements for transaction cards and identification recognizers, smart cards, etc.
Since 1987 when OFETs were reported, the performances of OFETs have been improved to some extent, and there is a great progress in the study on organic semiconductor materials. However, the performances in terms of thermal stability, chemical stability, mobility, etc., are still to be further improved.